谷氨酰胺对离体大鼠心脏缺血再灌注损伤的影响

目的研究谷氨酰胺对心肌缺血再灌注损伤时心功能和心肌酶的影响。方法30只sD大鼠取心脏建立Langendorff灌注模型，随机分为三组：（1）对照组（A组，正常灌注90min）；（2）缺血再灌注组（B组，全心缺血30min，复灌60min）；（3）谷氨酰胺组（c组，取心脏前3小时静脉注射谷氨酰胺0．75g/kg，全心缺血30min，复灌60min）。记录三组心脏的血流动力学水平，测定冠脉流出液肌钙蛋白I水平，测定复灌后心肌的热休克蛋白70水平。结果实与缺血再灌注组相比，谷氨酰胺组的左室发展压（LVDP）、左室内压上升/下降速率（±dp/dt）和心率明显增加，左室舒张末期压力（LVEDP）和肌钙蛋白I水平显著降低（P均〈0．05），谷氨酰胺组热休克蛋白70表达水平显著增加（P〈0．05）。结论谷氨酰胺能改善缺血再灌注损伤大鼠心脏的血流动力学，减轻心肌损伤，这些作用可能与其诱导热休克蛋白70表达相关。

The Effects of Glutamine on Ischemia/Reperfusion Injury in Isolated Rat Hearts

Objective The present study was designed to investigate the effects of glutamine on cardiac function and myocardial enzyme levels in ischemia/reperfusion insulted rat hearts. Methods Langendorff perfusion was performed from 30 SD rat hearts, which were randomly assigned to one of the three groups： the Control group （Group A, normal perfusion for 90 min）, the Isehemia/reperfusion group （Group B, global ischemia for 30 min followed by 60 min of reperfusion） and the Glutamine group （Group C, the rat received 0.75 g/kg glutamine intravenously 3h before the heart was harvested, which was then received global ischemia for 30 min followed by 60 min of reperfusion）. The hemodynamics, cardiac troponin I levels and heat shock protein 70 levels were recorded. Results Compared with the Ischemia/reperfusion group, glutamine increased left ventricular developed pressure, ：t：dp/dt, heart rate, and decreased left ventricular end-diastolic pressure and cardiac troponin I levels （P〈0.05）, meanwhile the heat shock protein 70 levels were enhanced （P〈0.05）. Conclusion Glutamine improves the hemodynamics and myocardial damage in ischemia/reperfusion insulted rat hearts, which may be related with glutamine-induced heat shock protein 70 expression.